A row has broken out between the union representing senior civil servants and Cabinet Office minister Francis Maude over his claim that Whitehall has "blocked" agreed government policy.

Maude was reported to have made the remarks as part of a speech at the Institute for Government on lessons for policy-making from New Zealand, one of the countries that will be used in the forthcoming IPPR thinktank review of how top civil servants are appointed and policy implemented. His speech, which was released in advance, said there had been cases where top civil servants in Whitehall had blocked initiatives.

The comments have infuriated the FDA. Dave Penman, the union's general secretary, said that by making accusations against permanent secretaries who are unable to defend themselves publicly, Maude risked "a severe loss of trust" between the most senior civil servants and ministers.

If ministers have concerns about the actions of permanent secretaries, said Penman, there are established ways of dealing with them. He added that it is the responsibility of civil servants to raise any serious concerns about policy initiatives with ministers. "Too often, ministers seek to scapegoat senior civil servants for the failure of policy," he said. "No chief executive of a major private company would publicly criticise his [sic] most senior managers in this way and not expect morale to plummet."

Penman said civil servants are working to implement the government's reform agenda and deficit reduction programme, while maintaining the standard of public services. "This is no way to motivate the most senior leaders to deliver this challenging agenda," he said.